said by l8r 
:Likewise, if you have other User JS files installed on your system, check Opera's JavaScript console
after logging into
dsl.sbc.yahoo.com. If you see any references to
undefined object, it's because the script presented in this post is destructive. Meaning: it deletes the
window.opera object that other User JS files may rely on. FYI, most User JS files simply expect the
window.opera object to exist, and don't check for its existence prior to accessing it.
This is correct, but this IMO is still the safest and most future-proof way to get around SBC's blocker. While your fix does not cause problems for other User JavaScripts such as this one does, it may not be as future-compatible against updates and changes in SBC's script. I will use my fix in browser.js because I can not check on a regular basis whether your fix still solves the problem without breaking anything.
